(a) Draw a neat, labelled ray diagram showing the formation of the final image in a…
PHYSICS · Subjective · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments
Problem
(a) Draw a neat, labelled ray diagram showing the formation of the final image in a compound microscope under normal adjustment. Clearly indicate the position and nature of the intermediate image.
(b) From the geometry of your diagram, obtain an expression for the lateral (linear) magnification produced by the objective in terms of the object distance uo and image distance vo.
(c) Hence derive a general expression for the overall magnifying power of the compound microscope in terms of tube length L, focal length of the objective fo, and focal length of the eyepiece fe when the final image is at infinity.
(d) If the objective focal length is reduced while keeping L and fe fixed, explain qualitatively how each term in your expression changes and why the overall magnification increases.